Paul Ducarme

'Countersnapping' structures shrink when pulled When you pull something—like a rubber band—you expect it to get longer. But what if it did the opposite? What if it suddenly shrank instead? In a study published in Proceedings of the National Academy of Sciences, researchers from AMOLF and ARCNL have made this possible. They created structures that snap inward when pulled outward.

12.05.2025 11:57 — 👍 1    🔁 1    💬 0    📌 0

Autonomous locomotion simply with tubes as limbs, and no brain? 🎈🤖

Yes, through physical synchronization! Our article is out today in Science (@science.org)

Article: www.science.org/doi/10.1126/...

Authors: @albertocomoretto.bsky.social, H.A.H. Schomaker, J.T.B. Overvelde

More below 🧪 ⚛️
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08.05.2025 18:15 — 👍 150    🔁 54    💬 12    📌 5

Our countersnapping metamaterial is featured in this week’s @science.org ‘s research highlights.

Full article in @pnas.org (open access)

doi.org/10.1073/pnas...

#metamaterial #mechanics #research #science #softmatter #countersnapping #braessparadox #amolf #arcnl #instability #counterintuitive

02.05.2025 08:12 — 👍 1    🔁 0    💬 0    📌 0

Special thanks to the Soft Robotic Matter group and co-authors Bart Weber, Martin van Hecke and Johannes T. B. Overvelde.

22.04.2025 16:27 — 👍 0    🔁 0    💬 0    📌 0

Exotic mechanical properties enabled by countersnapping instabilities | PNAS Mechanical snapping instabilities are leveraged by natural systems, metamaterials, and devices for rapid sensing, actuation, and shape changes, as ...

This work is part of my PhD at @amolf-nl.bsky.social and @arcnl.bsky.social. The findings have been published in PNAS: www.pnas.org/doi/10.1073/....

The article has been featured in the PNAS Showcase www.growkudos.com/publications....

Watch the highlight video
www.youtube.com/watch?v=Kxtk...

22.04.2025 16:26 — 👍 5    🔁 1    💬 1    📌 0

An object that shrinks as you pull it? This is physically possible! All you need is a piece of rubber with a weird shape. This is just mechanics and geometry.

This discovery reveals phenomena that defy intuition, and unlocks functionalities that could not yet be achieved in mechanical systems.

22.04.2025 16:24 — 👍 9    🔁 3    💬 1    📌 1

So cool 😎 getting-shorter-when-pulled mechanism.
youtu.be/KxtkcL0z5j0?...

18.04.2025 00:34 — 👍 4    🔁 1    💬 1    📌 1